Lecture 6 - Tinbergen's 4 questions

Question 1

What is ethology?

Answer 1

-scientific study of natural animal behaviour
-initially focussed on instinct but later incorporated learning
-mostly lead by European biologists in contrast to the North American psychologists leading behaviourism

Question 2

Who is Niko Tinbergen?

Answer 2

Naturalist and bird watcher who emphasised a combination of observation and experiments in the field and in the lab.
Originally worked in the Netherlands and was a prisoner of the Nazis.
His lab produced many of the most influential animal behaviour scientists in the 20th century.

Question 3

What was Tinbergen’s question surrounding Mechanism/causation?

Answer 3

What is going on in this animal right now?
- looks at cognitive, neurobiological, physiological mechanisms that causes behaviour
- proximate causation

Question 4

What was Tinbergen’s question surrounding ontogeny/development?

Answer 4

What in the past led to this behaviour in this animal?
- looking at the processes in the development in behaviour
- proximate causation

Question 5

What was Tinbergen’s question surrounding adaptive value/function?

Answer 5

What value does this behaviour provide?
- looks at why the behaviour exists at all for survival and reproduction
- ultimate causation

Question 6

What was Tinbergen’s question surrounding phylogeny and evolution?

Answer 6

What led to this species possessing this behaviour?
- looks at which species have certain traits and why - tracking evolutionary history of traits
- ultimate causation

Question 7

what is feature detection?

Answer 7

the correct stimuli can be defined by multiple aspects, including what it looks like and how it moves

Question 8

What are supernormal stimuli?

Answer 8

Stimuli are recognised by matching a template, but this template doesn’t need to exactly match the real stimulus.
Templates might include abstract combinations of shapes and other colours or involve “rules of thumb” such as incubate the largest round object.
These templates can be hacked by unnatural stimuli which better fit the internal rules.
We call these “Supernormal stimuli” and they can reveal how animal recognition works.

Question 9

What is fixed action pattern?

Answer 9

“Innate”, Species Typical, Fixed responses that are typically unlearned and performed in response to a trigger
Manipulation of releasers can result in hijacking of behaviour and a resulting arms race.

Question 10

How are complex animal behaviours organised?

Answer 10

Many vertebrate behaviours are more flexible than fixed action patterns.
But the idea of “innate” and species-typical behaviour raises questions about how complex behaviours are organised in the brain.

Question 11

Explain ethological action maps

Answer 11

mammals - motor action represented by maps in motor cortex of the brain
maps don’t correlate neatly with anatomy
new work suggests might be organised by natural behaviours
exciting different parts of the cortex result in monkeys carrying out complex actions

Question 12

what are hormones?

Answer 12

chemical messengers secreted by endocrine glands (or sometimes by neurons) and travel through the bloodstream

Question 13

How do hormones change behaviour?

Answer 13

By affecting the brain, specific muscles, or other organs.
They are slower than neurons but last longer, suitable for making changes over longer time periods.

Question 14

Explain the effects of oxytocin in sheep

Answer 14

normally olfactory bulb only reactive to food smells
parturition shift to response to lamb odours
mediated by oxytocin released by hypothalamus
hormones chance sensitivity of brain areas, leading to changes in learning and behaviour

Question 15

Explain the example of trial and error learning in portia (spiders)

Answer 15

When prey responds to a signal – Portia sticks with that signal.
if prey stops responding- portia sends signals again until finding ones that attract the prey

Question 16

Explain the Clayton and Dickinson 1998 experiment

Answer 16

Food-storing scrub jays
store favourite food (worm) and okay food (nut)
after 4 hours look for worms first
after 120 hours look for nuts first

Question 17

What does ontogeny ask?

Answer 17

how did this behaviour in this animal become what it is today?
often focus is on the early life experience but much bigger scope that that
how does an organism go from being a fertilised embryo all the way to being a behaving adults

Question 18

What are the different aspects of development?

Answer 18

growing up
- maturation
environmental influences
- Developmental induction
- Parental environment
- Resilience + equifinality
learning

Question 19

What is maturation?

Answer 19

Changes in behaviour due to physical changes in neural and muscular systems

Question 20

What did Hailman (1969) find in laughing gull chicks?

Answer 20

Increased pecking accuracy over first 2 days after hatching - found maturation occurred and not learning as even chicks that were reared in a dark environment had similar accuracy. Maturation > Learning

Question 21

What is development?

Answer 21

an interactive process in which genetic information interacts with changing internal and external environments
- No trait is “genetic” as opposed to “environmental”
- No trait is “environmentally determined” in the sense of developing without genetic input

Question 22

what happens when larvae are exposed to cold temperature?

Answer 22

lower learning ability
lower discrimination ability
poorer decision making
worse reproduction success

Question 23

What is the biotic influence in locust?

Answer 23

best grouping behaviour depends upon local population density
- 2 morphs (solitary, gregarious)
- which morph develops depends on number of collisions in early life
dependence on a particular factor for a trait to emerge is referred to as developmental induction

Question 24

What is phenotypic plasticity?

Answer 24

The ability of the organism to alter its phenotype in response to environmental input.
All learning is plasticity, not all plasticity is learning

Question 25

What is plasticity the outcome of?

Answer 25

natural selection and is dependent on genes - This means that something being learned is not the opposite of, or an alternative to, that thing being evolved

Question 26

Whats an example of a rearing environment?

Answer 26

prairie volves pups reared by both parents experienced more licking and grooming and were less exposed than those reared by the mother alone family structure influenced the environment developing pups experience

Question 27

What is an example of development and language learning?

Answer 27

In Japanese “Ra” and “La” are the same sound: ら. “Ba” and “Wa” however are two distinct sounds: ば and わ If you test compare Japanese native-speaking adults with English native-speaking adults. The latter are more sensitive to “ra” vs “la” but there is no different for “ba” vs “wa”

Question 28

What is channeling?

Answer 28

restricting early experiences make some outcomes more likely.

Question 29

What is self-regulation?

Answer 29

deviation form a developmental pathway results in correcting actions to compensate

Question 30

What is equifinality?

Answer 30

different developmental pathways can still lead to similar outcomes

Question 31

What are the general principles for the song development in birds (example of development)?

Answer 31

predisposition - neural template importance of experience - Juvenile hears song - Adult hears itself sing plasticity - Most birds - only sounds close to own song - Parrots, starlings - great variety of sounds sensitive period - song must be heard during first few months equifinality - as with language, many patterns of experiencing song produce normal song

Question 32

What is the difference between function and evolution's ultimate questions?

Answer 32

Function asks “What is this behaviour for?” based on studies of today’s animals. Evolution asks “How did this behaviour evolve?” by reconstructing evolutionary history.

Question 33

Example of functions of behaviour: gulls paddling

Answer 33

Why gulls paddle : Paddling results in worms coming to the surface paddling attracts males paddling scares potential predators - different potnetial hypotheses

Question 34

What did Stephen Gould and Richard lewontin criticise?

Answer 34

naive speculation about functions some features might not be specific adaptations but are actually byproducts of selection for a different trait

Question 35

What are the 3 main approaches to studying function in animal behaviour?

Answer 35

1. Observation – what are the natural consequences of the trait? 2. Experiment – does changing a trait change consequences? 3. Comparison – do similar problems result in similar solutions?

Question 36

Explain the first method to study function in animal behaviour (observation)

Answer 36

when there is a natural variation in a trait, measuring the consequences can suggest a possible function sparrows and finches add cigarette butts to their nest-fewer parasites

Question 37

Explain the second method to study function in animal behaviour (experiments)

Answer 37

no natural variation= creating variations using experiments allow us to better test the effect of a particular feature and we can keep all other factors the same

Question 38

e.g. why do gulls remove egg shells?

Answer 38

1. broken shells might hurt chicks 2. broken shells might prevent other chicks hatching 3. broke shells might make incubating difficult 4. broken shells might increase disease risk 5. broken shells might break camouflage - to test, Tinbergen & colleagues put out painted eggs with and without broken eggshells nearby. - found eggshells attract predators

Question 39

Explain the third method to study function in animal behaviour (comparison)

Answer 39

hard to test if behaviour associated with function if only compare similar species what we need is some diversity in both relatedness and behaviour

Question 40

Explain the example of ground nesting in comparison

Answer 40

aggressive to predators chicks don't avoid edges good chick recognition

Question 41

Explain the example of cliff nesting in comparison

Answer 41

less wary of predators chicks avoid edges less chick recognition

Question 42

explain function and evolution

Answer 42

similar problems lead to convergent evolution of stimuli solutions different problems lead to the divergent evolutions of different solutions shows behaviour

Question 43

How can we reconstruct evolution?

Answer 43

In Tinbergen’s time the main method was to identify homology – features that are the same because they come from a common ancestor.

Question 44

What counts as a species?

Answer 44

Carl Linnaeus (1707-78) developed a hierarchical categorization system based on how similar organisms are to one another.

Question 45

What is the difference between monophyletic and paraphyletic grouping?

Answer 45

monophyletic – contain all descendents of a common ancestor. paraphyletic - Groups that contain only some descendents of a common ancestor - many common kinds of animal are actually paraphyletic

Question 46

Explain the biological species concept (Mayr 1942)

Answer 46

a group of individuals capable of reproducing and producing fertile offspring together speciation is therefore result of reproductive isolation

Question 47

When is reproductive isolation more likely?

Answer 47

In populations that are further away from one another

Question 48

What are ring speces?

Answer 48

A special case thought to result from a continuous population expanding around a barrier. Although the two end populations cannot interbreed they are connected to a chain of populations that can

Question 49

What is meant by cladistics?

Answer 49

an approach which recognises that features can be both gained and lost over the course of evolution. Builds evolutionary trees based on most likely pattern of gains and losses given current traits. Today DNA is used to reconstruct evolutionary (or phylogenetic) tree, but we can use any observable sets of features

Question 50

Explain molecular clocks as a way of using DNA to date divergences

Answer 50

if neutral changes in DNA occur at a constant rate then we can also use degree of difference in DNA to date when lineages diverged variation in the rate of change affected by generation time, metabolic rate, natural selection requires some calibration for each application

Question 51

how can we reconstruct evolution?

Answer 51

today DNA is used to reconstruct evolutionary tree, but we can use the logic of cladistics to test sequences of behavioural evolution

Question 52

Explain the example of the evolution of dancing bees

Answer 52

honeybees communicate the location of good flowers to each other via waggle dance waggle dance contains info about the distance and direction of the flowers

Question 53

How can we plot the evolution of dancing bees?

Answer 53

1. use up-to-date phylogenetic tree 2. assign traits 3. determine simplest pattern of acquisition and losses reveals common origins and independent evolution

Question 54

what is the simplest solution for birds?

Answer 54

finding the simplest pattern of gains and losses isn't always easy among birds there are 3 groups capable of vocal learning these groups aren't closely related brain structures are very similar

Question 55

What did Hall et al find about what evolves first with old world babblers nests?

Answer 55

Hall et al. (2015) compared many species and found that that domed nests co-evolved with ground nesting. Domed nests in trees evolved first on the ground and then moved into trees. Suggests originally driven by predation

Question 56

What drives evolution of a trait?

Answer 56

The order of acquisition can tell us the factors that lead to a trait spreading in a population. Males in many species show exaggerated sexual characteristics that look like they require a lot of resources? How are these not removed by natural selection? Darwin (1871) suggested that these survive because females prefer these traits – and so they lead to higher reproduction.

Question 57

Sensory bias or male quality?

Answer 57

male swordtail fish have a distinctive sword on their lower tail the function of the sword is to advertise to females who prefer males with swords can test by comparing preference in the related platyfish species which do not have a sword